Addvice on Just Purchased 996 C2, Preventative Maintenance?

Hello, I just purchased a 1999, 996 C2 with 31,400 miles on it and am looking for advice on things to do immediately to guard against (as much is possible) a serious engine failure. I have spent a lot of time reading about 996’s in these forums but would appreciate any advice that anyone might care to give. I guess my first question would be is there any way this car with a manufacture date of 10/98 and engine serial # of M96/0166X03304 could have a single row IMS bearing? From what I have read it would seem highly unlikely/impossible? If not, that leads to the question with a 1%ish failure rate (double row), what if anything should I do with it? Would the age of the engine itself make the bearing seal degrade? Possibly altering the 1% failure rate in a bad way? Should I take the seals off? Add a DOF to the existing bearing? Replace? Also what about preemptive water pump (original as far as I can tell) and thermostat changes? I know the water pump can fail and maybe cause cooling blockage but is it worth changing it just cause of it's age before it goes bad? As for the thermostat, it runs at the proper temperature and both exhaust pipes are pristine with no soot. There is no knocking at idle. Maybe take it to have a leak down test? A bit late now but I was not able to have a PPI done. From the Carfax it looks like the car was owned by a corporate owner for 1 year/2000 miles, than owned by an individual for 15years/29000 miles at 2000 miles a year. The car was brought in to the shop once or twice a year for service for various reasons though sometimes it just says “servicing”. That’s the extent of the maintenance records I have. Thanks in advance.

Wow didn't paste well from Word... Sorry

There is really nothing pre-emptive that is needed, and if you get started replacing thigns before they fail then the list gets longer and loooonger. water pump may be the only item I would worry about because it is 'cheap and easy' to replace. it will fail eventually anyways. But again after that pre-emptive maintanence is really a waste when some part may outlive others for no particular reason. These cars are very reliable in general. just do regular oil chaneg and inspect your oil filters for bits and enjoy the car All big failure documented on the forum could not have been prevented by any kind of maintenance, short of pouring thousands to open the engine for no good reason. your early 99 model is apparently the most reliable based on recent forum comments so enjoy it not sure how much you paid for it, but remember that all maintenance you put it is money you will never get back so factor in the logic..."how much will it cost me if the engine blows up?' then think about your preventive care and the difference is the price of the gamble it is easy to spend $5k in preventive maintenance, when a used engine installed will cost you $10k...

If you feel you need to do anything to it. Change all fluids and that is all for now. You have 50000 miles to make up so simply drive it. You have the best year for a 996.

Water pump low temp therm AOS LNE spin on oil filter and mag plug Sounds like a great car

Look at the thread on the IMS. A dual row IMS does not eliminate a IMS failure. I have a 12/99 build car and was thinking of just letting it ride. However, there is speculation that a low mileage car is more likely to have an issue. My car has 378xx miles. If it has 90k miles my mechanic said to just leave IMS but given the low miles I opted to get it done. If I didn't get it done and IMS fails the car is a loss so you really have to weigh the cost benefit for yourself

If, if, if you are committed to keeping the car long term and its as nice as you seem to think (Get an outsider's opinion on this), I would invest in replacing the IMSB, AOS, etc., and any other components that flunk a close inspection by a skilled Tech. Then drive it regularly and enjoy! relinuca

If you do the IMS, go with the "solution." It actually increases the integrity of the IMS system, Otherwise just roll with what you have.

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But, does that $10K used engine have all that needs to be done to it?

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This would be my short list too, but I'd do it in two stages: 1) LNE spin on oil filter and magnetic drain plug right away with next oil change. 2) Water pump, low temp T-stat & Air Oil Separator, start shopping around for pricing, or plan on doing yourself.

Have some fun interviewing Indies in your area. Get to know who is the best before you need them. And if you plan a diy job, check here first to learn what is involved. Or read what an expert(not me !) says: https://www.specr53.com/blog/diy/har...ur-m96-engine/

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Looking through the IMS thread I couldn't find the rationale for the low mile failures for both types. Is it on older cars that have low miles but degraded seals from age? I did see where it is mentioned that during 2015 Flat6 was still getting two dozen dual row failures a year in their shop.. yikes! When you say low miles cars are possibly more likely are we talking going from 2% failure rates to 5%? 10%? 2% I can live with. Thanks

Thanks Jaetee. Sounds like a good plan! This would be my short list too, but I'd do it in two stages: 1) LNE spin on oil filter and magnetic drain plug right away with next oil change. 2) Water pump, low temp T-stat & Air Oil Separator, start shopping around for pricing, or plan on doing yourself.

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I better get started. Anyone in the San Diego area have recommendations? Thanks!

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Same here.

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I'll try to be brief with what I've learned in my year of researching this issue. At this point, it seems the prevailing thought is that the actual cause of IMSB failure (when it's just the bearing that fails, assuming no other issue caused the issue) the culprit is really a varying degree of rollout in the actual IMS Shaft. That would exlpain why both single and double row bearings are affected. Dual row can handle more of a beating, so if IMS Shaft has minimal rollout it may never fail, or take considerably longer. In general, the cars that experienced IMSB failure seemed to reveal the issue anywhere between 30-50k on the odometer. It's thought that cars that have lasted longer than than without issue have proven themselves to have a relatively straight IMS shaft and, in theory, to be less likely to experience the bearing failure. Of course there are always exceptions. Additionally, there was a fire at one of the Porsche engine plants sometime in mid 1999 that caused Porsche to hurriedly retrofit engines that hadn't passed quality control in order to keep production lines moving along. The cars made after that point (even with dual row bearings) were apparently more likely to experience the issue than those built prior. Hence the reason the early production 99's are considered the most reliable around here. I'm not sure the exact numbers quoted in the class action suit against Porsche lumps all of the 996 cars made from Dec 1997 to mid 2000 into one group with an IMSB failure rate around 1%. Cars made after mid-2000 to 2001 had a mix of dual and single row IMSB. I believe the 996 mk2 cars had a falure rate somewhere around 8-9%. The rationale behind "low miles / garage queen" cars being more succeptible to reveal IMSB issue is because they haven't driven enough miles to move the car into that "if it had a bad IMSB then it would have shown up by now" mindset. I would say that if the build date of your car is in 1998, you should be okay with just installing a magnetic drain plug (or maybe even IMSB Guardian) and monitoring for ferrous metal in your oil during changes. My 2000 had build date of May 2000, so I was right in that timeframe of uncertainty as to wheter I had dual or single row. And when I got the car I had 93k on the odo and it needed a clutch. I went ahead and had the IMSB changed as a precaution. The bearing that came out of my car was still seemingly perfect. No regrets.

IMSB Guardian no longer available through Flat Six...

Just to add confusion (!!) I recently picked up a January 1998 coupe that I intend to drive for a loooonnnnggg time!! So, although I know I am probably wasting money I want to give the car a clean start so am replacing IMS (ceramic, LN engineering), RMS, AOS and the clutch now. Together with a full maintenance and replacing the airco condensors (one was leaking, common issue) it will set me back 3300US$ which is fine by me. Important is that you have a qualified mechanic working on your car with the proper tools. Next on my list is cooling which I'd address with a higher capacity waterpump and low temperature thermostat. This is a 20 year old car and it makes sense to plan for some good maintenance in the coming period and not simply wait for stuff to fail. Anyway, just my 2c.

Pretty much in the same boat as you, got a low mileage MY '00 (Build Date 11/99) and nobody knows (including dealer) what type of IMS bearing my car has. So for now, I just change the oil every year regardless of mileage and check for metal bits. I also installed the LN Mag-drain plug. If your car still has the OEM engine mounts than it's a good idea to replace them now. It will make your car tighter/quieter and will improve handling. Cheers,

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Look up PCNA for San Diego - ask them.They know all the answers.

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$3300 for all that work? Where are you, Mexico?

LOL! The Netherlands! Check it out below: https://youtu.be/ELD2AwFN9Nc Volkert

Thanks for all the great info!

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I've nether been there, bet the pixies are all super cool in Nether-netherland.

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That has got to be the funniest Trump video I've ever seen. Really... it's true, it's great!!

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It's a fantastic video, it's true. The editor has tremendous talent - the best talent, in fact. He's so talented they could barely cut him a check - believe me, it was a LOT of money. Not too much money for me, of course, because I'm very rich - so rich you wouldn't believe, it's true. I've had tremendous success and led a wonderful life.